The present invention relates to rotary sprinklers, such as are used in water irrigation systems for irrigating crops.
A common form of rotary sprinkler includes a nozzle producing a jet axially of the nozzle, a rotor located and configured to receive the axial jet and to deflect it laterally of the nozzle, and a bridge secured to the nozzle and including a leg formed with a socket vertically aligned with the nozzle for rotatably mounting the rotor. Such rotary sprinklers have a tendency for rotating at a high velocity, which decreases the effective range of the sprinkler. These sprinklers are therefore frequently provided with a friction surface, such as a friction ring, between the rotating rotor and the fixed nozzle to retard or brake the rotor. However, such friction surfaces are not completely satisfactory since the retarding effect imparted by them tends to change in the course of time as the surfaces wear, thereby requiring frequent adjustment or replacement of sprinkler parts.
An object of the present invention is to provide a rotary sprinkler of the foregoing type which includes an improved arrangement for retarding the rotation of the rotor.